Locomotive boiler



Mai-ch 3, 1931. H. E. YARROW ET AL I 7 1,795,241

LOCOMOTIVE BOILER Filed .Jan. 17, 1929 5 Sheets-Sheet 1 March 1931. E. YARROW ET AL I 1,795,241

LOCOMOTIVE BOILER Filed Jan. 1'7, 1929 5 Sheets-Sheet 2 I I ayezzz d fie ZZ Z1 Ya v OCOOOOOOOOOOOOOQO000000000000 .1 0 O CO oo o 00 000 ooooooooooooooooo oon March 3, 1931 H. E. YARROW ET AL LOCOMOTIVE BOILER Filed Jan. 17, 1929 5 Sheets-Sheet 5 March 3, 1931. H. E. YARROW ET AL LOCOMOTIVE BOILER Filed Jan. 17, 1929 5 Sheets-Sheet 4 March 3, 1931. H. E. YARROW ET AL 1,

LOCOMOTIVE BOILER Filed Jan. 17. 1929 5 Sheets-Sheet 5 Even Zora Jerald Z: )Qrr ow J i M. 621242? Patented Mar. 3, 1931 UNITED STATES. PATIENT orFlcn HAROLD YABROW, OF GLASGOW, SCOTLAND, .AND HERBERT NIGEL GRESLEY, OI HADLEY WOOD, ENGLAND LOCOMOTIVE BOILER Application filed January 17,1929, Serial No. 338,070, and in Great Britain January 17, 1928.

According to the present invention a central fiue is provided between the two forward (1 water drums and their banks of tubes, and also two outside flues, and the hot gases from the combustion space are constrained to pass therefrom into the central flue, and thence amongst the forward banks of water tubes to the outside flues which lead to the smokebox, so that the furnace gases are compelled to pass across the tubes and not in the longitudinal direction of the banks of tubes. Further, a secondary combustion chamber is provided at the back of the usual firebrick arch of the firebox in which the combustion of the gases is completed after they pass over the arch. This secondary combustion space surrounds the rear ends of the two forward water drums, and is confined at its forward end, except as regards the centre portion, by a transverse firebriek screen, and the water tubes connecting the parts of the forward water drums within the secondary combustlon space are of a special character as compared with the generality of the water tubes which connect the larger forward portions of,

the water drums with the steam drum; that is to say these special tubes are of heavier scantling and larger diameter than the remainder of the tubes, .and are curved outwardly to a greater extent so as to leave a wider space between them.

The two sets of water drums, namely the firebox water drums and the forward additional water drums, are arranged parallel or slightly inclined with the steam drum, the palr of drums in-front of the firebrick arch being preferably at a higher level than the firebox water drums, and considerably closer together, leaving, however, sufficient space between the two forward banks of generating tubes to accommodate a superheater. 4

The fire door end of the firebox is preferdrum in a known manner.

ably provided with an arrangement of screen tubes radiating from the steam drum and connected with a transverse header or water In the present invention the transverse header is discontinuous, consisting of two separate headers extending inwardly one from each of the two firebox water drums. Shouldathe firing of the boiler be of such a character as' not to reuire the provision of a fire door at the rear end of the firebox, these screen tubes would extend over the whole rear end of the firebox, but even in this case the inwardly projecting headers should not be continuous, so as to allow freedom of the water drums to have a slight transverse movement.

The invention will be more specifically described with reference to the accompanying drawings, wherein Fig. 1 is a longitudinal section and Fig. 2 a sectional plan showing the general arrangement of a locomotive water tube boiler embodying the invention; Fig.

3 is atransverse section the right half of which is taken on line A-A and the left half.

on line 13-13 of Fig. 1, while Fig. 4 is a transverse section taken as to the right half on line CC and as to the left half on line D-D of Fig. 1, in every case looking towards the front end of the boiler; Figs. 5 and 6 are respectively a longitudinal section and a sectional plan on an enlarged scale of the rear part of the boiler, while Fig. 7 is a transverse section taken as regards the left half on line E-E and as regards the right half on line F--F of Fig. 5; Fig. 8 is a longitudinal section ofthe principal parts of the boiler showing the method of supporting same, while Fig. 9 is a rear end elevation and Fig. 10 a front end elevation thereof; Fig. 11 is a longitudinal section of the rearend of the boiler taken on line H-H of Fig. 12, which is a transverse section taken on line I-'I'of Fig. 11; Fig. 12 is an enlarged scale view of a detail; Fig. 13 is a longitudinal sectionjof the front part of the boiler showing the arrangement for heating feed water, and Fig. 14 is a transverse section on line J-J of Fig. 13.

Referring first mainly to Figs. 1-4, the

boiler has a single steam drum a extending vided.

As shown in the drawings, the boiler is adapted to be coal-fired, but the fire box may be modified to suit the use of other forms of fuel, such as pulverized coal or oil, in either of which cases it may be more convenient to introduce the fuel at the front end of the fire box.

The water drums b, b are connected with the steam drum a by water tubes 6 which form the two sides of the fire box, and the forward water drums c, 0 are connected with the steam drum a by water tubes f. All the steam and water drums are parallel with each other, and the water drums b are spaced as far apart as possible to give maximum space in the fire box, while the forward water drums a approximate more closely towards each other, preferablyleaving, however, suflicient space to accommodate between them a superheater 0?.

The rear end of the fire box, with the exception of the fire door in the case of a hand-fired boiler, is preferably provided with an arrangement of screen tubes g radiating from the steam drum a and connected with inward- I 1y extending headers h which are themselves in direct connection with the back water drums b, 6. Should the firing of the boiler be of such a character as not to require the provision of a fire door at the rear end of the fire box, the screen tubes 9 would be arranged to extend over the whole rear end of the fire box, but even in such a case it is preferred that the inwardly projecting headers h, it should not be continuous across the boiler, so as to allow freedom for the water drums b, b to have a slight transverse movement. Access to the headers 72. may be obtained through hand-holes situated on the under sides of the headers and one of which, n, is shown on an enlarged scale in Fig. 12

Referring now mainly to'Figs; 5, 6 and 7, the products of combustion from the fuel burned on the firtgrate 0 pass over the fire brick arch i into a continuation'g of the fire box combustion space, and the water tubes within this space connecting the front water drums c with the steam drum a are of a special character as compared with the generality of the water tubes 7 connecting the larger portion of the water drums c with the steam drum. These tubes are of heavier scantling and larger diameter than the tubes 7, and are curved outwardly to a greater extent, so that there is a wider space between the inside tubes 1) than there is between the inside tubes f, which latter are, as shown in Fig. 6, of smaller diameter.

The front end of this supplementary combustion space g is closed, all except the centre portion, by a transverse fire-brick screen 7', so that a considerable proportion of the combustion gases from the space 9 has to pass amongst the tubes 30 to get to the central flue a; between the generating tubes f. From this flue the gases pass amongst the tubes f into the outside longitudinal flues s, 8 on either side and thence to the smoke box.

The steam drum a is rigidly'secured near its forward endto a fixed rigid front support 7' secured to .the frame of the locomotive and the rear end of the steam drum is supported on a flexible plate mconnecting the steam drum with the framework of the locomotive. The front water drums a, 0 are supported in fore and after sliding bearings 0, 7c and the back water drums b, b are similarly supported in fore andaft bearings Z, Z. These bearings are of such a character as to permit the water drums to move freely fore and aft while restrained from lateral movement. It is, however, necessary to provide sufiicient clearance in the bearings k, l to enable the flexible plate m to function properly when there is expansional or contractible movement of the steam and water drums.

As shown more particularly in Figs. 13 and 14, the steam drum a is prolonged beyond the forward ends of the water drums 0 into the smoke box, and this part of the steam drum is divided from the remainder into which the steam generating tubes are expanded by a transverse division plate 25 extending upwards above the normal water level. All the feed water is led into this front part of the steam drum, where it is heated by the furnace gases on their way from the smoke box to the smoke stack and overflows the partition t into that part of the steam drum which the generating tubes enter, any deposit-having thus the opportunity of settling in the comparatively quiet water in the forward end of the steam drum. The usual feed water non-return or check valve u is provided and in addition there may be also a screw-down valve a after pass ing which the water enters a feed heater '0 within the steam space of the boiler of such a character that the feed water in passing through the heater entrains steam from the boiler and is thereby heated very nearly to the temperature of the saturated steam. From the feed heater '0 the feed water is discharged into a feed water trough 11 of iarg cross section, whereit is reduced in vlelecit and heated still further by contact with the steam, and from this feed water trough, which extends over the partition t, it is allowed to flow gently into the feed water reservoir w plonstituting the forward end of the steam rum. 1

Having thus described the nature of the said invention and the best means we know of carrying the same into practical effect, we claim ing a steam drum and two pairs of water drums, a rear pair and a forward pair, banks of water tubes connecting the steam drum with the several water drums, said rear drums and associated tube banks enclosing a firebox and combustion space, a central flue between the banks of tubes of the forward water drums, two flues outside the said forward banks of tubes leading to the smoke box, and transverse bafiles extending across said outside flues and constraining the hot gases from the combustion space topasstherefrom into the central flue.

2. A locomotive water tube boiler accord ing to claim 1., wherein the water tubes connecting the steam drum with the ortions of the two forward water drums w ich are in rear of the transverse baflles are shaped to provide a wider space between themthan the space between the remainder of the forward banks of water tubes. v

'3. A locomotive water tube boiler according to claim 1, wherein the water tubes connecting the steam drum with the portions of the two forward water drums which are in rear of the transverse bafiiesare of heavier scantling and larger diameter and are sha ed to provide a wider space between them t an the space between the remainder of the forward banks of water tubes.

4. A locomotive water tube boiler com-.

prising a steam drum, four separate water drums one on either sideof the fire box or primary combustion space of the furnace,

and the remaining two disposed side by side forward of said space, water tubes connecting the steam drum with the several water drums, a fire-brick arch at the front end of the said primary combustion space, a supipllementary combustion space forward of the re-brick arch and surrounding the rear por- -tions of the two forward water drums, a

transverse fire-brick screen closin all but a central part of the front. end of t e supplementary combustion space, a central flue between the banks of watertubes of the front I water drums, and outer flues arallel therewith in front ofthe'transverse rebrick screen leading to the smoke box.

5. A locomotive water tube boiler according to claim 1, wherein the rear pair of water drums are disposed one on either side of the fire box or primary combustion space of the furnace and the rear end of the said fire box is provided with screen tubes radiating from the steam drum in. two groups, each group being connected with headers extending inwardly from the said rear water drums.

\ '6. A locomotive water tube boiler comprising a steam drum and a plurality of water drums disposed belowand parallel with the steam drum and banks of water tubes conwater drums, wherein the steam drum is 1. A locomotive water tube boiler compris-- ported on sliding bearings permitting longitudinal movement of the drums in conformity with any longitudinal expansional movement of the steam drum. 7. A locomotive water tube boiler according to claim 1, comprising a steam drum extending forwardly into the smoke box beyond the front ends of the forward water drums, and a partition partially dividin off this forward portion of the steam drum rom the remainder to form a feed water reservoir.

8. A locomotive water tube boiler comprising a plurality of longitudinally disposed water drums, a steam drum above and parallel with said water drums extending forwardly beyond the said water drums, banks of water tubes connectin the steam drum with the several water rums, a partition partially dividing off this forwardly extending portion of the steam drum from the remainder to form a feed water reservoir, a support rigidly connecting the forward end of the steam drum with the locomotive frame, a flexible su port connecting the rear end of 

